Watercraft having low cavitation drive

ABSTRACT

A watercraft comprises a hull which is bouyant in water, and a propulsion system coupled to the hull for for propelling the hull in the water. The propulsion system comprises a propulsion disc and at least one drive input coupled to the propulsion disc. The propulsion disc is rotatable by the drive input about an axis of rotation and comprises a cavitation-reducing ring and a plurality of paddles extending radially outwards from the cavitation-reducing ring, The cavitation-reducing ring is configured to reduce cavitation in the water during rotation of the propulsion disc.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims the benefit of the filing date of U.S. patent application Ser. No. 60/851,321, entitled “Turbo Boat”, filed Oct. 13, 2006, and U.S. patent application Ser. No. 60/851,322, entitled “Stingray Boat”, filed Oct. 13, 2006.

FIELD OF THE INVENTION

The invention described herein relates to a self-propelled watercraft. In particular, the invention relates to a pedal-powered watercraft.

BACKGROUND OF THE INVENTION

Conventional pedal-powered watercraft are typically implemented as a kayak or a catamaran, and comprises a human-powered propulsion system. The propulsion system comprises a paddlewheel which is supported on a rotatable crankshaft. The paddlewheel creates cavitation in the water as the paddlewheel is rotated. As a result, the transfer of input pedal energy to watercraft movement is inefficient.

SUMMARY OF THE INVENTION

The invention relates to a watercraft propulsion system that includes an inertial cavitation reduction mechanism.

In accordance with one aspect of the invention, there is provided a propulsion system that comprises a propulsion disc and a plurality of paddles. The propulsion disc has a central axis and comprising a cavitation-reducing ring. The paddles extend radially outwards from the cavitation-reducing ring. The cavitation-reducing ring is configured to reduce cavitation in water during rotation of the propulsion disc about the central axis.

In accordance with another aspect of the invention, there is provided a watercraft that comprises a hull which is bouyant in water, and a propulsion system coupled to the hull for propelling the hull in the water. The propulsion system comprises a propulsion disc and at least one drive input coupled to the propulsion disc. The propulsion disc is rotatable by the drive input about an axis of rotation and comprises a cavitation-reducing ring and a plurality of paddles extending radially outwards from the cavitation-reducing ring, The cavitation-reducing ring is configured to reduce cavitation in the water during rotation of the propulsion disc.

In one implementation, the propulsion disc has a pair of opposing sides, and comprises at least one aperture disposed radially outwards from the axis of rotation and extending axially between the opposing sides. The cavitation-reducing ring is disposed radially outwards from the at least one aperture, and comprises a pair of cylindrical walls each extending axially outwards from a respective one of the opposing sides.

Further, the propulsion disc also comprises a support ring that is disposed around a circumference of the disc. Each paddle includes an outer end and extends radially outwards from the cavitation-reducing ring and terminates at the respective outer end. The support ring is coupled to the paddles at the outer ends thereof.

The drive input may comprise comprises a pedal provided on a crankshaft, and the propulsion disc may comprise a keyed centre that is configured for receiving the crankshaft therein. The keyed centre is concident with the axis of rotation.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of the watercraft, according to the invention;

FIG. 2 is a perspective view of the hull of the watercraft shown in FIG. 1;

FIG. 3 is a perspective view of the propulsion disc of the watercraft;

FIG. 4 is a side elevation of the propulsion disc when the watercraft is deployed in water;

FIG. 5 is an end view of the propulsion system;

FIG. 6 is an exploded schematic view of the propulsion system;

FIG. 7 is a top perspective view of one of the seats of the watercraft;

FIG. 8 is an exploded view of the seat shown in FIG. 7;

FIG. 9 is a side elevation of the seat;

FIG. 10 is a bottom perspective view of the seat;

FIG. 11 is a perspective view of the bimini top of the watercraft;

FIG. 12 is a schematic view of a bimini mount when the bimini top is in the closed/inclined position;

FIG. 13 is a schematic view of the bimini mount when the bimini top is in the closed/down position;

FIG. 14 is a perspective view of the bimini mount when the bimini top is in the open position;

FIG. 15 is a perspective view of the bimini mount without the bimini top;

FIG. 16 is a perspective view of the hull, depicting the storage locations of the propulsion discs;

FIG. 17 is a magnified view of the bow of the hull;

FIG. 18 is a magnified top view of the seat back attachment mechanism of the seat shown in FIGS. 7 and 8;

FIG. 19 is a magnified bottom view of the seat back attachment mechanism;

FIG. 20 depicts the propulsion discs proximate the hull mounting locations thereof;

FIG. 21 is a bottom perspective view of the watercraft;

FIG. 22 is a top perspective view of the watercraft;

FIG. 23 is a perspective view of one variation of the propulsion disc shown in FIG. 3; and

FIG. 24 is a magnified view of the propulsion disc shown in FIG. 23

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in FIGS. 1 and 16, the watercraft, according to the invention, is hydrodynamically-stable, and comprises a low profile catamaran hull 1, and a hood 2.

Preferably, the watercraft uses a dual independent drive system that allows for the left and right peddlers to pedal independently of each other and at their own pace. The dual independent drive system comprises a pair of turbo propulsion discs 4 and a pair of crankshafts 5. Each crankshaft 5 is supported by a pair of crankshaft bearings 32, 33, and is secured at one end to a corresponding propulsion disc 4. FIG. 5 depicts the left and right propulsion discs 4 and the left and right crankshafts 5, and associated crankshaft bearings 32, 33.

FIG. 6 depicts one of the crankshafts 5 prior to being installed into the corresponding propulsion disc 4. FIG. 6 also reveals the design of the crankshaft bearings 32, 33, and the location of the crankshaft bearings 32, 33 relative to the crankshafts 5. As shown in FIG. 2, the hull 1 includes recesses 23, 24 that are formed into the top surface of the hull 1 and retain the crankshaft bearings 32, 33 therein. The crankshaft bearings 32, 33 are open ended or substantially U-shaped in design to allow the propulsion disc 4 s and the crankshafts 5 to be quickly and easy installed into the hull 1 from the top of the hull 1. FIG. 21 depicts the propulsion disc 4 s and the crankshafts 5 installed into the hull 1.

Preferably the crankshaft bearings 32, 33 are tapered inwardly adjacent their open end to thereby retain the crankshafts 5 within the crankshaft bearings 32, 33. Further, preferably the crankshaft bearings 32, 33 are dimensioned relative to the recesses 23, 24 such that, when the crankshaft bearings 32, 33 are inserted into the recesses 23, 24, and the crankshafts 5 are installed into the crankshaft bearings 32, 33, the crankshafts 5 urge the crankshaft bearings 32, 33 slightly outwards to thereby retain the crankshaft bearings 32, 33 in the recesses 23, 24.

The propulsion disc 4 is best shown in FIGS. 3 and 4. As shown, each propulsion disc 4 includes a ring 27 disposed around the centre of the propulsion disc 4, and a series of paddles 26 extending outwards from the ring 27. Each propulsion disc 4 also includes a plurality of apertures or through-holes 29 that extend axially between the opposing sides of the disc 4. As shown in FIG. 4, the ring 27 is disposed radially outwards from the inner series of apertures, and reduces cavitation and turbulence in the water when the propulsion disc 4 is being rotated about its centre of rotation, thereby creating more propulsion power. The propulsion disc 4 also includes an outer ring 28 surrounding the paddles 26 that allows the propulsion disc 4 to be used as a wheel to move the turbo boat around on land, or between land and water. Further, the propulsion disc 4 includes a keyed centre 30 which is disposed at the centre of rotation, and is configured to receive one of the crankshafts 5 therein.

One variation of the propulsion disc is shown in FIGS. 23 and 24. The propulsion disc depicted therein includes a plurality of paddle extensions 26 a. As shown, each paddle extension 26 a slides over the outer end of one of the paddles 26 and snaps onto the outer ring 28, thereby locking the paddle extension into place. Preferably, the paddle extensions 26 a are fabricated from soft PVC, thereby imparting resilient properties to the paddle extension. As a result, the paddle extensions 26 a, when attached to the paddles 26, increase the efficiency and propulsion ability of the propulsion disc. Although the propulsion disc is shown comprising a paddle extension for each paddle 26, the propulsion disc may be fitted with fewer paddle extensions 26 a, depending upon the desired efficiency of the propulsion disc.

FIG. 17 is a magnified view of the hood 2, and the front portion of the hull 1. As shown in FIGS. 1, 16 and 17, the two-component hull and hood design constitutes a change in traditional thinking of the forms of pedal boats from bulky designs to a low profile sleek design with the propulsion disc 4 positioned to the front center of the hull 1 at mid level of the hull 1. This two-component design, in conjunction with the design of the crankshaft bearings 32, 33, allows the propulsion disc 4, crankshafts 5 and the crankshaft bearings 33 to be easy installed into the hull 1 from the upper surface of the hull 1.

As shown in FIGS. 16 and 17, the hood 2 includes a pair of hinge pins 51 disposed on opposite sides of the hood 2. The hinge pins 51 are received in corresponding channels 55 formed in the top surface of the hull 1, thereby allowing the hood 2 to be quickly installed into the low profile sleek hull 1. The channels 55 also allow the hood 2 to be rotated rearwardly about the hinge pins 51, into a retracted position (FIG. 20), to thereby facilitate installation and removal of the propulsion discs 4 and the crankshafts 5.

The hood 2 also includes a tongue 53 at the rear portion thereof, and a pair of lock lips 52 disposed on opposite sides of the hood 2. When the hood 2 is rotated from the retracted position into the closed position (FIG. 22), the lock lips 52 engage the crankshafts 5 at the uppermost portion of the crankshaft bearings 32, 33. The tongue 53 also frictionally engages the hull 1, thereby causing the lock lips 52 to lock the crankshafts 5 into the crankshaft bearings 32, 33.

As shown in FIG. 2, the hull 1 includes a wet self-cleaning and bailing hole 16. When the turbo boat is placed in the water, a thin layer of water is allowed on the floor of the hull 2 (through the bailing hole 16). When the boat is lifted out of the water, this thin layer of water drains out through the bailing hole 16, thereby washing the upper surface of the hull 2 as it exits through the bailing hole 16. There is also a plug (not shown) to seal the bailing hole 16.

As shown in FIGS. 1, 2 and 16, the hull 2 includes a cavity molded into the upper surface thereof for store the propulsion disc 4 when not in use. This feature reduces transportation costs in mass production movement.

As shown in FIG. 1, preferably the turbo boat includes a pair of rearwardly facing chairs 3. The turbo boat also includes a pair of frontwardly facing chairs 3 (not shown). As shown in FIGS. 7 to 10, each chair 3 comprises a seat 40 and a backrest 34. Preferably, the backrest 34 has three (3) integrally molded arms extending downwards from the lower end of the backrest 34. As shown in FIGS. 8 and 18, each arm includes a locking pin 36 disposed at the end of the arm, and a pivot pin 35 disposed between the locking pin 36 and the lower end of the backrest 34.

As show in FIGS. 18 and 19, the seat 40 has three (3) key-type holes 54 extending through the seat 40, adjacent the rear portion of the seat 40. The key-holes 54 are dimensioned to receive a respective one of the backrest arms therein. Further, each key-hole 54 includes a pair channels 56 that extend laterally outwards from the centre of the key-hole 54 to receive and support a respective one of the pivot pins 35.

Further, as shown in FIG. 19, the seat 40 includes a series of integrally-molded shallow channels 39 formed on the underside of the seat 40. When the backrest arms are inserted into the key-holes 54 of the seat 40, the pivot pins 35 are received within a pair of channels 56, thereby supporting the weight of the occupant's back. The locking pins 36 are also received within one of the shallow channels 39.

As shown in FIG. 9, by rotating the backrest 34 forwards about the pivot pins 36, the locking pins 36 can be positioned within any one of the shallow channels 39, to thereby allow the user to adjust the angle of the backrest 34 as desired. As a result, the chair 3 can be configured in various positions to allow for various sizes of occupants.

The bimini assembly 43 is depicted in FIG. 1 and FIGS. 11 to 15. As shown, the bimini assembly 43 comprises a pair of support rods 41, a bimini top 44 secured to the support rods 41, and a bimini mount 45 supporting and securing the support rods 41. As shown in FIGS. 14 and 15, the bimini mount 45 includes a pair of mounting holes 48 for securing the bimini mount 45 to the hull 1, and a pair of rod clamps, each terminating in a pair of opposed unlocking fingers 46, 47. Each rod clamp is configured to receive and retain one of the support rods 41 therein. Each support rod 41 is also pivotally secured to the bimini mount 45 preferably via a respective aluminum pin 50 that extends through the respective rod clamp and support rod 41. This configuration of the bimini mount 45 allows the bimini top 44 to be deployed in one of the following three (3) positions: open (FIGS. 11 and 14), closed/inclined (FIG. 12) and closed/down (FIG. 13) to thereby shield the boat occupants from the sun, as desired. 

1. A watercraft comprising: a hull bouyant in water; and a propulsion system coupled to the hull for propelling the hull in the water, the propulsion system comprising a propulsion disc and at least one drive input coupled to the propulsion disc, the propulsion disc being rotatable by the drive input about an axis of rotation and comprises a cavitation-reducing ring and a plurality of paddles extending radially outwards from the cavitation-reducing ring, the cavitation-reducing ring being configured to reduce cavitation in the water during rotation of the propulsion disc.
 2. The watercraft according to claim 1, wherein the paddles are substantially resilient.
 3. The watercraft according to claim 1, wherein the propulsion disc has a pair of opposing sides, and comprises at least one aperture disposed radially outwards from the axis of rotation and extending axially between the opposing sides, and the cavitation-reducing ring is disposed radially outwards from the at least one aperture.
 4. The watercraft according to claim 3, wherein the cavitation-reducing ring comprises a pair of cylindrical walls each extending axially outwards from a respective one of the opposing sides.
 5. The watercraft according to claim 4, wherein the drive input comprises comprises a pedal provided on a crankshaft, and the propulsion disc comprises a keyed centre configured for receiving the crankshaft therein, the keyed centre being concident with the axis of rotation.
 6. The watercraft according to claim 4, wherein the propulsion disc further comprises a support ring disposed around a circumference of the disc.
 7. The watercraft according to claim 6, wherein each said paddle includes an outer end and extends radially outwards from the cavitation-reducing ring and terminates at the respective outer end, and the support ring is coupled to the paddles at the outer ends thereof.
 8. A propulsion system for watercraft, the propulsion system comprising: a propulsion disc having a central axis and comprising a cavitation-reducing ring; and a plurality of paddles extending radially outwards from the cavitation-reducing ring, the cavitation-reducing ring being configured to reduce cavitation in water during rotation of the propulsion disc about the central axis.
 9. The propulsion system according to claim 8, wherein the paddles are substantially resilient.
 10. The propulsion system according to claim 8, wherein the propulsion disc has a pair of opposing sides, and comprises at least one aperture disposed radially outwards from the central axis and extending axially between the opposing sides, and the cavitation-reducing ring is disposed radially outwards from the at least one aperture.
 11. The propulsion system according to claim 10, wherein the cavitation-reducing ring comprises a pair of cylindrical walls each extending axially outwards from a respective one of the opposing sides.
 12. The propulsion system according to claim 11, wherein the propulsion disc comprises a keyed centre configured for receiving a crankshaft therein, the keyed centre being concident with the central axis.
 13. The propulsion system according to claim 11, wherein the propulsion disc further comprises a support ring disposed around a circumference of the disc.
 14. The propulsion system according to claim 13, wherein each said paddle includes an outer end and extends radially outwards from the cavitation-reducing ring and terminates at the respective outer end, and the support ring is coupled to the paddles at the outer ends thereof. 